Terminal construction



July 1957 w. A. BARNES 2,799,840

- TERMINAL CONSTRUCTION Filed June 2, 1953 FIG. I FIG. 2 FIG. 3 FIG. 4-

ll FIG. l2

' Min 4 M it/Ma, 1M

ATTYS INVENTOR.

TERIVIINAL CONSTRUCTION William A. Barnes, Utica, N. Y., assignor toUtica Drop Forge & Tool Corporation, a corporation of New YorkApplication June 2, 1953, Serial No. 359,159

8 Claims. (Cl. 339-275) This invention relates in general to terminalconstruction for electrical conductor wires, and relates morespecifically to terminals adapted to be united to the conductor wire bya cold phase bond and having a thin metallic coating of another metalover the surfaces of the anchor terminal portion.

The terminal of this invention may be constructed according to theteachings set forth in application Serial Number 343,745.

An object of this invention is to provide a terminal constructionadapted to be cold welded with a solid phase bond to a conductor wire.

Another object of this invention is to provide a terminal of aluminumfor aluminum conductor wires, and having a copper facing on the surfacesto be attached to an electrical device.

Other objects and a fuller understanding of this invention may be had byreferring to the following description and claims, taken in conjunctionwith the accompanying drawing, in which:

Figure 1 is an end view of a blank bar from which a terminal may be madeaccording to the principles of this invention;

Figure 2 is a side view of the blank bar;

Figure 3 is an end view of the blank b'ar processed to provide -a stubconnected end shaft on each end thereof;

Figure 4 is a side view of the blank bar as thus processed;

Figure 4-A is an end view of an alternate connector end constructionwherein a central stub shaft and a concentric ring collar is provided oneach end thereof;

Figure 4B is a longitudinal sectional view through the alternateconstruction;

Figure 5 is an end view of an intermediate step in the production of aterminal wherein a second metal is applied to the surface of the blank,and the blank forged to shape the portion for the anchor area and tobond the second metal to the faces of the anchor area with a solid phasecold formed bond;

Figure 6 is a side view of the intermediate step;

Figure 7 is an end view similar Figure 5, but with the surplus edgestrimmed away;

Figure 8 is a top view of a finished double terminal as formed from theintermediate step of Figure 6 by trimming and punching; 1

Figure 9 is a top view of the terminal of Figure 8 as divided into twoindividual terminals;

Figure 10 is an illustration of a conductor wire and a single terminalin position to be united;

Figure 11 is a view of the wire and terminal united with a cold-weldsolid phase bond; and

Figure 12 illustrates the reinforcement of the connection by folding ofthe concentric ring of Figure 4-B over the union.

The cold welding or uniting of metal by the production of a solid phasebond under conditions of controlled pressure and confinement of flow isset forth basically in Patent No. 2,522,408, issued to Sowter.Application Seria itg States ater No. 343,745, filed March 20, 1953,sets forth a teaching of the reinforcement of such solid phase union bythe provision of a clamp member. The drawing in that applicationillustrates a terminal embodying some of the features illustrated inthis drawing and described herein.

This application pertains principally to the terminal construction andthe method of making the terminal construction rather than to thereinforcement of the juncture between two members welded by a coldformed solid phased bond.

In the process of this invention there is provided a blank bar 10 of anysuitable size and shape. In the drawing of this application, the blankbar 10 is illustrated as being a round bar as readily available frommany suppliers. Square bars and other shapes are equally suitable. InFigures 3 and 4, the blank bar is illustrated as having been providedwith a stub shaft 11 on both ends thereof. The stub shaft may beprovided by machining away metal of the blank bar, or by extruding ifdesired.

In Figures 4A and 4-B, there is illustrated an alter nate method ofproviding a stub shaft suitable for coldweld solid phase bonding :to aconductor. In these figures, a central stub shaft 12 and a concentricring collar 13 are provided on each end of the blank bar. Shaft 12 andring 13 are preferably provided by upset extrusion, but may be providedby machining methods if desired.

Regardless of what manner is used for providing the stub shaft 11 or thestub shaft 12, the cold union of that shaft to a conducting wire may becarried out as explained in the application Serial No. 343,745 and maybe reinforced by the ring collar 13 as also described in thatapplication.

Terminals suit-able for solid phase cold-weld bonding are preferablyprovided in the same material as the con ductor wire to which it isintended that they be joined. In the event that the terminal is to beconnected to a copper conductor then, undoubedly, a copper terminal willprove more satisfactory. In such event, the blank bar 10 is forged inthe central area to provide a roughly formed anchor portion which may betrimmed to proper size and provided with suitable attachment holes. Whena blank bar is provided with a stub shaft on both ends as illustrated inFigure 4 and forged into a shape substantially as illustrated in Figure6, it may be trimmed and used as a double terminal, or divided as shownin Figure 9 to form two individual terminals. No further processing needbe carried out to produce a servicable terminal.

However, copper is becoming increasingly scarce and expensive Whereas,the light metals, such for example as "aluminum, are becoming moreplentiful. Aluminum has many other characteristics which also make itdesirable for electrical conductors regardless of the comparativescarceness and cost. However, the provision of terminals for aluminumwire and a relatively loose surface contact between aluminum and copperwill produce excessive corrosion. Consequently, the use of aluminum wireconductors has been hampered because of the lack of a suitable terminal.

According to this invention, the blank bar 10 is provided with opposedlayers of a second metal, preferably copper, and the two metals forgedtogether into the form illustrated in Figures 5 and 6 of the drawing. Byconducting the forging under controlled conditions of pressure and flow,a solid phase bond at a temperature less than the normal weldingtemperature of the two metals is accomplished. Two separate pieces ofthe second metal, usually copper, may be placed on opposed sides of theblank bar 10 or a tube of the second metal may be slipped over thecentral portion of the blank ba-r prior to forging. In many respects theuse of a tube is preferable to the use of separate pieces, asillustrated in Figure 5.

In order to produce a successful union between the two metal layers thesurface of the metals must be prepared by cleaning and roughening of thesurfaces as described in the Sowter Patent No. 2,522,408.

As related with respect to the production of a solid metal terminal, forexample, a copper terminal, the blank screw for attachment of theterminal to an electrical appliance. If the terminal is to be used as adouble connector, it is allowed to remain in one piece as illustrated inFigure 8, and if a single end conductor is to be produced, the area 14is divided to produce two individual terminals 16, as illustrated inFigure 9.

In Figure 10 of the drawing, there is illustrated a single terminal 16and a wire conductor 17 in aligned positions ready to be joined by asuitable tool which will drive the ends of the wire 17 and shaft 11together under conditions of confined flow and high pressure. Anindication of the type of tool which may be used for this purpose isillustrated in application Serial No. 348,069. The ends of the shaft 11and the wire 17 must be properly prepared for such solid phase bonding.

Figure 11 illustrates the terminal 16 and the wire 17 joined. The solidphase bonding by this method produces a flange 18.

In Figure 12 of the drawing, the reinforcement of the flange 18 isillustrated. In Figure 12, the blank bar illustrated in Figure 4-13,after having been processed as de scribed with respect to the blank barof Figure 4, is attached to the stub shaft 12 and the collar 13 foldeddown around the resulting flange 18.

The Figures 10, 11 and 12 are intended to illustrate the appearance ofan aluminum wire 17 and an aluminum terminal body with the opposed fiatsurfaces of the anchor portion provided with covering plates 19 and 20of copper bonded to the aluminum body by a solid phase bond.

The mechanical contact of copper and aluminum, regardless of how tightlythey are held in contact, tend to set up a galvanic action whichproduces corrosion. Thereby, the direct connection of an aluminumterminal to a copper connector body is undesirable. Furthermore, thereare other well-known reasons why copper is preferred for a face-to-faceconnector surface. By providing the plates 19 and 26 on the surface ofthe aluminum terminal body by a cold-phase bond, the galvanic action ismaterially reduced to a practical level. The terminal then has theadvantage of copper contact faces for mechanical contact with connectorbodies.

Although this invention has been described in its pre ferred form with acertain degreee of particularity, it is understood that the presentdisclosure of the preferred form has been made only by way of exampleand that numerous changes in the details of construction and thecombination and arrangement of parts may be resorted to withoutdeparting from the spirit and scope of the invention as hereinafterclaimed.

What is claimed is:

1. An electrical terminal, comprising, a terminal body of a first metal,said terminal body having a contact portion and connector portionadapted to be connected to a conductor wire, an external layer ofanother metal over the surfaces of the contact portion of said body,said external layer united to said body solely by a cold weld solid 4phase bond produced by pressure and characterized by the absence ofthird substance bonding agents.

2. An electrical terminal, comprising, a terminal body of aluminum, saidbody having a fiat anchor portion, an external layer of copper onopposed sides of said anchor portion, said copper united to said anchorportion solely by a cold-weld solid phase bond.

3. The method of producing electrical terminals, comprising the stepsof, providing a blank bar of a first metal, providing a stub shaft onsaid blank bar suitable to be welded to the size of wire to be joined tosaid terminal, cleaning and preparing the surface from a portion of saidblank bar suitable for solid phase bonding, placing said preparedportion within opposed layers of a second metal, compressing saidprepared portion and layers of the second metal under forging pressureand at a temperature less than normal welding temperature for said firstand second metals until a portion of said blank bar is flattened into ahat anchor portion of a thickness less than half the thickness of theblank bar, said second metal thereby being bonded to the surface of thefirst metal on said anchor portion by a cold weld solid phase bond.

4. The method of producing an electrical terminal, comprising the stepsof, providing a blank bar of aluminum, providing a stub shaft on saidblank bar suitable to be welded to the size of wire to be joined to saidterminal, cleaning and preparing the surface from a portion of saidblank bar suitable for solid phase bonding, placing said preparedportion within opposed layers of copper, compressing said preparedportion and layers of the copper metal under forging pressure and at atemperature less than normal welding temperature for said aluminum andcopper metals until a portion of said blank bar is flattened into a fiatanchor portion of a thickness less than half the thickness of the blankbar, said copper metal thereby being bonded to the surface of thealuminum metal on said anchor portion by a cold weld solid phase bond.

5. The method of producing an electrical terminal, comprising the stepsof providing ablan'k bar of a first metal, providing first and secondstub shafts on opposite ends of said bar suitable to be welded to thesize of wire to be joined to said terminal, cleaning and preparing thesurface from a portion of said blank bar between said stub shaftssuitable for solid phase bonding, placing said prepared portion withinopposed layers of a second metal, compressing said prepared portion andlayers of the second metal under forging pressure and at a temperatureless than normal welding temperature for said first and second metalsuntil said portion of the blank bar is fiattened into a flat anchorportion of a thickness less than half the thickness of the blankbar,said second metal thereby being bonded to the surface of the first metalon said anchor portion by a cold weld solid phase bond.

6. The method of producing electrical terminals, comprising the stepsof, providing a blank bar of aluminum metal, providing first and secondstub shafts on opposite ends of said bar suitable to be welded to thesize of wire to be joined to said terminal, cleaning and preparing thesurface from a portion of said blank bar between said stub shaftssuitable for solid phase bonding, placing said prepared portion withinopposed layers of copper metal, compressing said prepared portion andlayers of the second metal under forging pressure and at a temperatureless than normal welding temperature for said aluminum and copper metalsuntil said portion of the blank bar is flattened into a fiat anchorportion of a thickness less than half the thickness of the blank bar,said copper metal thereby being bonded to the surface of the aluminummetal on said anchor portion by a cold weld solid phase bond. y

' 7. The process of making a terminal for uniting to a conductor wirecomprising the steps of, providing a bar of aluminum, extruding acentral stub shaft and concentric ring collar on each end of said barpreparing a portion of the surface of said bar suitable for solid phasebonding, placing said prepared portion within opposed layers of copper,compressing said prepared portion and layers of the copper metal underforging pressure and at a temperature less than normal weldingtemperature for said aluminum and copper metals until a portion of saidblank bar is flattened into a flat anchor portion of a thickness lessthan half the thickness of the blank bar, said copper metal therebybeing bonded to the surface of the aluminum metal on said anchor portionby a cold weld solid phase bond, and finally dividing the forged centerportion to produce two individual terminals.

8. An electrical terminal comprising a terminal body having a solid stubshaft and concentric collar encompassing said stub shaft, a solidconductor rod aligned with said stub shaft within the confines of saidcollar and united with said stub shaft by a cold weld solid phase bondto form a flash flange at the joint formed by said union, and saidcollar being pressed tightly against said flash flange in supportingengagement therewith.

References Cited in the file of this patent UNITED STATES PATENTSMiddleton Feb. 24, Hill Nov. 15, McTighe June 5, Merritt Aug. 9, ReckerSept. 27, Mendel Nov. 28, Cummins Mar. 5, Brickman et al. Apr. 12,Melchior Mar. 5, Bergan Sept. 16, MacInnes Aug. 10, Odlum Aug. 17,Martines Jan. 10, Rogoff July 4, Keene Sept. 22, Rood Jan. 26, Duch May4, Sowter Jan. 4,

